1 介绍
$?命令：可以得到上次执行命令的值，如果返回时0，说明执行成功，如果是其它数说明命令执行失败
联合使用命令：我们一般这样使用
1. value=$(cat 1.txt | grep chenyu) 2. echo $value
2 代码测试
#/bin/bash pwd="pwd" ll="l+" $pwd if [ $? -eq 0 ]; then echo "pwd executed success" else echo "pwd executed fail" fi $ll if [ $? -eq 0 ]; then echo "l+ executed success" else echo "l+ executed fail" fi cmd=$(ls | cat -n); echo $cmd value=$(cat cmd.sh); echo $value
3 运行结果
/home/chenyu/Desktop/linux/dabian/shell pwd executed success ./cmd.sh: line 15: l+: command not found l+ executed fail 1 1.txt 2 back 3 cmd.sh 4 cmd.sh~ 5 color.sh 6 color.sh~ 7 funcion.sh 8 funcion.sh~ 9 IFS.sh 10 IFS.sh~ 11 shuzu.sh 12 shuzu.sh~ 13 test.sh 14 test.sh~ #/bin/bash pwd="pwd" ll="l+" $pwd if [ $? -eq 0 ]; then echo "pwd executed success" else echo "pwd executed fail" fi $ll if [ $? -eq 0 ]; then echo "l+ executed success" else echo "l+ executed fail" fi cmd=$(ls | cat -n); echo $cmd value=$(cat cmd.sh); echo $value
